Hello Customer (name blocked for privacy) and welcome to JustAnswer!
These papers are supposed to be 356 years old official papers, I figure they must be very expensive antiquities, if they are real.
The most accurate method is to ask a radiocarbon laboratory to perform a carbon age test. It will give the age of the paper, but I have no idea how much it may cost. Here's a relatively cheap laboratory in UK:
http://www.gla.ac.uk/nercrcl/
In USA a simple radiocarbon test including sample preparation costs about $300 (slightly more than 150 pounds). If it's too expensive in UK and you are interested in sending a sample page to USA here's the lab website:
http://www.geochronlabs.com/14c.html
Hope this helps but if you have any further questions please let me know.
Have a great weekend!
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